/**
 * @Author wtzhhh
 * @create 2021/3/31 上午 11:00
 */
public class Sub {
    public int sub(int m, int n) {
        // 前置断言
        assert n >= 1 && n <= 99;
        assert m >= 1 && m <= 99;
        assert m - n >= 0;

        return m - n;
    }
}
